So basically he is saying that we will never ever know how really big the universe is. It’s because we can’t see anything that is beyond 15Billion light years due to the expansion of universe is faster than the speed of light. The fact that we are loosing 20k stars per seconds on our line of sights speaks how fast the universe is expanding. This is very fascinating!

Don, these vids are brilliant. Questions like this one have always bothered the hell out of me (like this one, or the apparent change in the speed of light through different transparent media). I was just resolved but not happy that answers would not be available 'cause it appeared I was the only one asking these questions. Take a bow man, this is a huge service to myself, and now I can say, all of nerd-kind. Much appreciation.

Some thought experiments:

Seems to me given the area the universe is encompasses today it would be very hard for it to be expanding slower than it did shortly after the big bang.

A simpler way to explain it is that, if something expands from a single point, its perimeter will be a continually-expanding sphere. In any sphere, the diameter is twice the distance from the centre, so you would expect the distance from any point to the centre to be a lot shorter than the diameter. The reason it's more than double is more complex.

If it takes time for parts of the universe to become visible from earth (as an example location not geocentrism - feel free to pick your own) and it's expanding so parts that can be seen in one instance will be unseeable in later instances, is there a time to live or have lived that it is possible to be able to see the most numbers of stars or galaxies?

if everybody leaves their toast in for 8 minutes....this could account for most of the dark matter in the universe

I always thought nothing is faster than the speed of light, but a what speed is the universe expanding?

The moment you realize that time does not exist, then ... everything is getting clear.

It’s fun to think that the stars you look at in a telescope may have become a supernova yesterday but we won’t know it for several thousand years

Explicación perfecta, gracias. Me he suscrito.

Would it be possible to make dark matter? If so, how would we do it?

Basically space is expanding so fast it’s decreasing our render distance

Another way to propose this question might be : How could anyone accurately know how old the universe is or how wide it is?

Although this will make some people's heads spin, it answered questions I had well. Even though there may not be any humans still around at that far away date, it is amazing that the skies will be less and less populated visually. I am sad for future beings who will look up at the night sky and mostly see darkness.

Mind blowing! Now if someone could only explain to me where the Moon goes when we can't see it at night? ;)

Everything explained very clear. Except that I was waiting to hear that the speed of light isn't actually the limit, since the speed of expansion of the universe is much bigger. I'm still waiting to hear that.

Every year, new discoveries of galaxies farthest from our own are made 👍

I swear this man has a body language of a quest-giving NPC

Lincoln should make another video on this same topic explaining better such an important issue, he should reivindicate his level as one of the best science popularizer pound-for-pound